The proposed research will provide information on the metabolism of plasmalogens, their precursors and structural analogues in the developing rat brain. The structural specificity of glycerol ether formation, glycerol ether cleavage and plasmalogen formation will be studied in vivo by intracerebral injection of C14- and H3-labeled precursors and the results will be substantiated by in vitro experiments using microsomal fractions of developing rat brain. Various saturated and unsaturated, straight chain and branched chain alcohols, alkanediols and alkaneketols and their glycerol ether derivatives are available to serve as substrates. The occurrence and metabolism of phospholipids having a long-chain 1,2-alkanediol backbone will be investigated. Preliminary results indicate that these lipids occur in small amounts in mammalian brain and liver. The metabolism of phytol (3,7,11,15-tetramethyl-2-hexadecenol) and the incorporation of its metabolites into ether and ester moieties of neutral and polar brain lipids will be investigated. The origin of phytanic acid which accumulates in large quantities in heredopathia atactica polyneuritiformis (Refsum's disease), a relatively rare lipodosis, is still unexplained.